package lab02.test06;

public class Circle {
    double r;
    public static final float PI = 3.1415f;


    //行为
    public void area() {
        double ar;
        ar = PI * r * r;
        System.out.println("圆的面积为：" + ar);
    }

    public void perimeter() {
        double pe;
        pe = 2 * PI * r;
        System.out.println("圆的周长为：" + pe);
    }
}
